Effects of Change in Tongue Pressure and Salivary Flow Rate on Swallow Efficiency Following Chemoradiation Treatment for Head and Neck Cancer

Patients treated with chemoradiation for head and neck cancer frequently develop dysphagia. Tissue damage to the oral tongue causing weakness along with decreases in saliva production may contribute to dysphagia. Yet, effects of these variables on swallowing-related measures are unclear. The purpose of this study was (1) to determine effects of chemoradiation on tongue pressures, as a surrogate for strength, and salivary flow rates and (2) to elucidate relationships among tongue pressures, saliva production, and swallowing efficiency by bolus type. Twenty-one patients with head and neck cancer treated with chemoradiation were assessed before and after treatment and matched with 21 healthy control participants who did not receive chemoradiation. Each participant was given a questionnaire to rate dysphagia symptoms. Videofluoroscopic Evaluation of Swallowing (VFES) was used to determine swallowing efficiency; the Saxon test measured salivary flow rate; and the Iowa Oral Performance Instrument (IOPI) was used for oral tongue maximum and endurance measures. Results revealed significantly lower tongue endurance measures for patients post-treatment as compared to controls (p =.012). Salivary flow rates also were lower compared to pre-treatment (p =.000) and controls (p =.000). Simple linear regression analyses showed that change in salivary flow rate was predictive of change in swallow efficiency measures from pre- to post-treatment for 1 mL thin liquid (p =.017), 3 mL nectar-thick liquid (p =.026), and 3 mL standard barium pudding (p =.011) boluses. Based on these findings, it appears that chemoradiation treatment affects tongue endurance and salivary flow rate, and these changes may impact swallow efficiency. These factors should be considered when planning treatment for dysphagia.